//The MIT License

//Copyright (c) 2009 Lluis Sanchez, Nick Darnell

//Permission is hereby granted, free of charge, to any person obtaining a copy
//of this software and associated documentation files (the "Software"), to deal
//in the Software without restriction, including without limitation the rights
//to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//copies of the Software, and to permit persons to whom the Software is
//furnished to do so, subject to the following conditions:

//The above copyright notice and this permission notice shall be included in
//all copies or substantial portions of the Software.

//THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//THE SOFTWARE.

using System;
using System.Reflection.Emit;

using Polymorph.Properties;

namespace Polymorph
{
    public class CodeWhile : CodeStatement
    {
        private CodeExpression m_condition;
        private CodeBlock m_whileBlock;

        public CodeWhile(CodeExpression condition)
        {
            m_condition = condition;

            if (condition.ResultType != typeof(bool))
            {
                throw new ArgumentException(String.Format(Resources.ExpMustHave0Result,
                    "bool"), "condition");
            }
        }

        public override void Generate(ILGenerator gen)
        {
            Label startLabel = gen.DefineLabel();
            Label checkLabel = gen.DefineLabel();

            gen.Emit(OpCodes.Br, checkLabel);
            gen.MarkLabel(startLabel);
            m_whileBlock.Generate(gen);
            gen.MarkLabel(checkLabel);

            if (m_condition is CodeConditionExpression)
            {
                ((CodeConditionExpression)m_condition).GenerateForBranch(gen, startLabel, true);
            }
            else
            {
                m_condition.Generate(gen);
                gen.Emit(OpCodes.Brtrue, startLabel);
            }
        }

        public override void PrintCode(CodeWriter cp)
        {
            cp.Write("while (");
            m_condition.PrintCode(cp);
            cp.Write(") {");
            cp.EndLine();
            cp.Indent();
            m_whileBlock.PrintCode(cp);
            cp.Unindent();
            cp.BeginLine().Write("}");
        }

        public CodeBlock WhileBlock
        {
            get { return m_whileBlock; }
            set { m_whileBlock = value; }
        }
    }
}